Regulating means for battery-charging.



w. L. Buss.

REGULATlNG MEANS FOR BATTERY CHARGING.

APPLICATION FILED APR.29. l 9ll.

Putnted Nov. 12, 1918:

2 SHEETSSHEET I.

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W. L. BLISS.

REGULATING MEANS FOR BATTERY CHARGING.

APPLICATION FILED APR. 29. WI].

II I

III

IIIII I I I I I I WI E UNITED STATES PATENT OFFICE.

WILLIAM L. BLISS, OF NIAGARA FALLS, NEW YORK, ASSIGNOR, BY MESNE ASSIGN-MENTS, TO U. S. LIGHT & HEAT CORPORATION, OF NIAGARA FALLS, NEW YORK, A

CORPORATION OF NEW YORK.

REGULATING-MEANS FOR BATTERY-CHARGING.

Specification of Letters Patent.

Patented Nov. 12, 1918.

Application filed April 29, 1911. Serial N 0. 624,111.

To all whom it may concern:

Be it known that I, WILLIAM L. Buss, a citizen of, the United States,residing at Niagara Falls,'in the county of Niagara and State. of NewYork, have invented new and useful Improvements in Regulating Means forBattery-Charging, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specification.

This invention relates to electric car light- 1ng systems. y

It is applicable also to other systems of electrical distribution inwhich a storage battery is to be charged.

Electric car lighting systems such as are now usually employed inpractice, have a generator which is driven from a car axle and suppliescurrent to a storage battery and lamps. When the generator runs at a lowspeed or is at rest, the storage battery furnishes the current to thelamps. An automati switch is provided which connects the storage batteryand lamps to the generator when the critical speed is reached, that is,When the speed is suflicient to cause the generator to produce a voltagewhich is approximately equal to the normal batteryvoltage. When thespeed is below the critical point,

the automat c switch opens so that'the battery will not dischargethrough the generator. An automatic regulator is provided to regulatethe generator so that the output thereof will remain within prescribedlimits notwithstanding the variations in speedto which the generator issubjected. The usual regulator is electro-responsive and varies thefield strength of the generator by means of resistance.

. The generator should supply suflicient current during the time theautomatic switch is closed to light the lamps and also to recharge thebattery to com ensate for the current which the battery urnishes to thelamps while the generator is inactive. The current taken from thebattery and the time the generator is in operation vary from timeto'time. Accordingly, aiiy regulator which is set so as to cause thegenerator to deliver a definite current to the battery fails to meet-.-the actual requirements. The system .should battery.

An object of this-invention is to provide means which will-cause thegenerator to supply sufiicient current to the battery to compensate forthe discharge thereof and further to control the voltage applied to thebattery when it is fully charged.

Another object is to provide means which will cause the generator tosupply current to the battery until a definite charge is attained andwill then reduce the generator voltage.

Another object is to provide improved means for varying the eneratoroutput in response to predetermined conditions of charge in the battery.

In accordance with this invention, as it is preferably arried out, anelectro-responsive regulator is provided which regulates the generatorto confine its output within prescribed limits throughout variations inspeed while it is operating above the critical speed. A meter isemployed to measure the input and output of the battery. This metercontrols means which alters the standard of operation of the regulatorwhen the battery is fully charged, so that the volta e of the generatorwill be maintained su cient to supply the lamps without forcing aninjurious overcharge into the battery. This voltage is that best adaptedto the battery employed. In many systems this will be the batteryfloating voltage so that the battery is subjeeted neither to charge nordischarge. In some systems it may be desirable to so adjust theregulator as to permit a small current in a charging direction to flowinto the battery. The character ofregulation decar lighting systemembodying the invention.

The views of the drawing are as follows Figure 1 is a diagram of the carlighting system.

Fig. 2 is a' diagrammatic representation of the ampere hour meter.

Fig. 3 is a diagram of a modification ofthe system.

The car lighting system has a generator provided with an armature 1 anda shunt field winding 2. The generator supplies a main circuit 3, 4,across which the storage battery 5 and lamps 6 are connected in parallelbranches.

The automatic switch 13 connects the battery and lamps t0 the generatorwhen the generator .voltage is substantially equal to the normal batteryvoltage. The lifting or closing coil 14 of the-switch is connectedacross the generator terminals and when the predetermined voltage isattained, the coil closes the switch. A series coil 15 assists inholding the switch closed. If the generator voltage falls below thebattery voltage, the battery will discharge through the series coil andby thus reversing its polarity, cause it to oppose the lifting coil andopen the switch.

The generator is regulated by a variable pressure rheostat which isconnected in series with the field winding. The resistance member of therheostat is formed of a series of contacting electrodes of carbon orother suitable material, the resistance of which varies with variationsin pressure exerted thereon. The rheostat is controlled by a. series orcurrent coil 8 and a shunt or voltage coil 9. These coils actuate aplunger which varies the pressure on the electrodes by means of a bellcrank lever.

The current winding is in series with the battery and lamps and tends tokeep the generator current constant, while the shunt wlndin is connectedacross the generator termina s and tends to keep the generator voltageconstant.

The shunt winding is normally inert, it being short-circuited by ashort-circuiting relay. The relay has a short-circuiting arm 10 normallyimpelled upward by a spring but adapted to open the short circuit uponthe energization of the voltage responsive wmdmg 11 connected across thegenerator terminals and responsive to the voltage of the latter. Thecoil 11 is normally connected 1 across thesystem 'throu h a resistance11.

The resistanceis of su cient value to prevent the coll 11 becomingefi'ective at ordijnary voltages across the system. Means are rovided,under the control of the meter, as

. iiereinafter explained, to short-circuit the rexsistance 11' underpredetermined conditions and thereby to permit a suflicient current toflow through the coil 11 to render it effective.

An auxiliary coil 12 on the relay is connected across the relay contactsand hence is short-circuited when the relay short-circuits the coil 9.The coil 12 is wound to oppose the action of the winding 11, when therelay contacts are 0 en. The short-circuiting arm 10 is adapte tovibrate rapidly, whereby the voltage responsive winding 9 is cut intoand out of circuit for successive short intervals ata rapid rate. Theeffectiveness of the winding 9, therefore, is governed by the characterof vibrations of the relay. Suitable fuses 12' are provided in thegenerator lead 3 and circuit of the shunt coils which operate therheostat and relay.

The arrows adjacent the coils 8, 9, 11 and 12 indicate the direction ofpull exerted by the cOils on their respective cores.

Of course, other forms of rheostats may be substituted or differenttypes of generator regulators employed to control the generator output.a

An integrating meter 18 is connected-in the battery circuit to measurethe number of ampere hours supplied to the battery or dischargedthereby. Suitable means are provided in connection with this meter forreducing the generator output when. the battery has received apredetermined charge.

the meter, shown more particularly in Fig. 2, has a motor rovided withan armature 19 rotating in t e field of 'a permanent magnet 20. Thismotor rotates one way or the other, depending on whether the battery isbeing charged or discharged. It drives a recording train of wheels 21,which operate a' pointer 22 providedwith a contact adapted to cooperatewith the relatively fixed adjustable contact 23. The pointer indicatesthe state of charge of the battery on a suitably calibrated dial.

If the meter only measured the actual current put into the battery andthat discharged thereby, it would not at all times accurately indicatethe state of the battery charge. 10 This is because of the internal andother battery losses. These are compensated for by causing the meter torun faster when measuring a' battery discharge than when measuring abattery charge. The ratio be- 11 tween these speeds depends on theparticular battery and is made proper to just compensate for the batteryinefficiency. The change. in rate is accomplished by a resistance 24 inv the armature circuit of the meter motor. This resistance is preferablyadjustable and is adapted to be short-circuited by the polarized relay25. The resistance 26, in shunt to the motor armature, prevents fullbattery charging current from passing through the armature. The relay 25opens the short circuit around the resistance .24 when the battery isbeing charged and closes the short circuit when the battery is beingdischarged, so that the motor rotates at a lower speed in the lampvoltage.

Assume, to illustrate the operation of the meter, that the battery is a200 ampere hour battery, that is, one which when fully charged willdeliver a 200' ampere hour discharge, and that its internal and otherlosses are approximately 15%. Because of the 15% losses it will requireapproximately 235 ampere hours to completely charge the battery. When,therefore, approximately a 235 ampere hour charge has been supplied tothe battery, the meter will indicate a full charge. When the battery hasdischarged 85% of its charge, that is, 200 ampere hours,

it will be depleted. The meter'is thereforeadjusted so that whenapproximately a 235 ampere hour charge has been delivered, the meterwill indicate 200 ampere hours and upon the discharge of 200 amperehours, it will indicate zero charge. Thus, at any instant, the meteraccurately indicates the state of battery charge.

When the battery is fully charged, the meter closes the circuit at theycontact 23, thereby short-circuiting the resistance 11 and causing aneffective current to flow in the voltage coil 11 which is now connecteddirectly across the system.

The lamp circuit may be controlled by a switch 16 and any suitable formof lamp regulator 17 may be employed to regulate The operation of thesystem is as follows: When the generator is at rest, the automaticswitch is open and the-battery supplies any current required for thelamps. The regulator coils are deenergized so that the resistance of thefield circuit is a minimum. Consequently, when the generator armature isrotated, the voltage will rapidly build up until it substantially equalsthe normal battery voltage. The automatic switch closes and thegenerator supplies the lamps-and begins to charge the battery. When thegenerator current reaches a predetermined maximum, the current coil 8will begin to insert resistance into the field circuit to cause thispredetermined current' to be maintained constant, regardless of furtherspeed increases of the generator. 1A decrease in speedand consequenttendency to decrease in current'will cause the coil to reduce theresistance in the field circuit and thus maintain the predeterminedoutput.

The current flowing to the battery operates the meter and moves thepointer to in-- dicate the ampere hours delivered to the bat tery. Thecontacts of the meter close the short circuit around resistance 11', andthus cause energization ofthe relay coil 11 when suflicient current hasbeen measured by the meter to bring the battery to full charge. The coil11 opens the relay contacts, thus causing energization of the voltagecoil 9 of the regulator. The coil 12 is also ener gized to oppose thecoil 11, when the relay opens. The coil 9 co-acts with the current coil8 and immediately causes an increase in the resistance of the fieldcircuit. The resultant drop in generator voltage reduces the force ofthe coil 11 and this, with the opposin force of the coil 12, instantlycauses t e coil 11 to release its core so that the relay contacts closeand again shortcircuit the coil 9. The operation is repeated and therelay arm 10 vibrates at a rapid rate. The efiective energization of thevoltage coil 9 is controlled by the character of the vibrations of therelay arm. The adjustment is such that the coil 9 is just suificientlyenergized to reduce the generator voltage to any desired value andmaintain it at this value, notwithstanding speed changes of thegenerator. In practice it is genera ly desirable to reduce the generatorvoltage sufliciently to cause the battery to float across slightly abovethat of the battery at the instant the meter contacts are closed. The

additional current supplied to the battery when it is substantiallyfully charged, will cause its counter electro-motive force tovriserapidly, with the result that a rapidly taates the meter in thereverse direction and 4 at the faster rate to compensate for the batterylosses. This opens the meter contacts and restores the regulatorcircuits to their former condition so that the battery will be rechargedas soon as the generator becomes operatlve. r

Fig. 3 illustrates a modification in which the meter contacts directlycontrol the circuit of the coil 9. Otherwise, this system is the same asthat illustrated in Fig. 1. As soon as the meter indicates a fullcharge, the coil 9 is fully energized and immediately reduces thegenerator voltage to the desired value and keeps it at this value. Thiscauses an immediate reduction in the generator current suflicient toprevent current being supplied to the battery to overcharge it. In thisfigure many of the details have been omitted for the sake' of clearness.1

It is apparent that the generator regulator acts in response to theamount of batterycharge actually received and is not dependent on therising voltage ofthe system or some other characteristic of thebattery.-

of course, susceptible of various modifications and changes, all ofwhich will embody the invention and be Within the appended claims.

What I claim is- 1. In combination, a variable source of supply, astorage battery to be charged thereby, means for measuring the chargeand discharge of the battery, regulating means for said source, andmeans controlled by said measuring means for varying the standard ofoperation of said regulating means when a predetermined batterychargehas been measured.

2. In an electrical system, a variable source of supply, a regulator forsaid source, a storage battery to be charged thereby, a load circuit tobe supplied by said source or said battery, means for 'measuring thecharge and discharge of said battery, and means controlled by saidmeasuring means for varying the standard of operation of said regulatorwhen a predetermined battery charge has been measured.

3. In a car lighting system, a generator, a storage battery to becharged thereby, a regulator for reducin the generator output when thebattery is fully charged, and means in series with the battery fordetermining the point at which said regulator shall reduce the generatoroutput.

4. An electrical system having a .storage battery, regulating means tocontrol the current supplied to the battery and the voltage applied-thereto, and means connected in series with they battery for causingthe regulating means to maintaina reduced voltage after a predeterminedcharge has been sup plied to thebattery.

5. In an electrical system, a storage battery, means for supplyingcurrent thereto, means for regulating the value of the current suppliedto the battery, and means influenced by the product of the time andquantity of current supplied to the battery, and cooperating with saidregulating means to cause said regulating means to reduce the value ofthe current after a predetermined quantity has been supplied to saidbattery.

6. In an electrical s stem of generation and regulation, a varia lesource of supply, a storage battery to be charged thereby, a regulatorfor maintaining a predetermined output from said source, means formeasuring the current supplied to said battery or discharged thereby,and means under control of said measuring means whereby the output ofsaid source may be maintained at a value above said predetermined output.controlle causing said source to deliver current to the 8. Incombination, a variable speed gen erator, means for regulating thegenerator output, a storage battery to be charged'by said generator, ameter in the battery circuit to measure the charge and discharge of saidbattery, and means controlled by the meter for varying the standard ofoperation of the regulating means when a predetermined battery chargehas been measured by said meter.

9. In an electrical system, a stora e battery, means for supplyingcurrent tIiereto, means for regulating the current supplied to thebattery, means influenced by the amount of current supplied to thebattery and-cooperating in t e operation of said regulating means toreduce the current after a predetermined amount has been supplied.

1 In an electrical system, a source of current having a predeterminednormal output, a battery charged thereby, means for measurin thecharging current and means by said measuring means for system at areduced rate when a predetermined amountof charge has been delivered tothe battery.

11. In combination, a variable speed generator having a predeterminednormal output, a storage batter charged thereby, a meter for measuring te charge delivered to the battery, and means controlled by said meterfor causing said enerator to maintain a predetermined re uced outputwhen a predetermined battery charge has been measured.

12. In an electrical system including a storage battery, a source ofsupply, means for regulating said source, means for measuring thecurrent supplied to said battery by said source, said means alsomeasuring the current discharged by said battery, said measuring meansalso afiecting said regulating means when a predetermined battery chargehas been measured, and means whereby said measurin means may permit morecurrent to enter said battery than is discharged therefrom beforeafiecting said regulating means, thereby compensating for batterylosses.

13. In a battery charging system, means for measuring the currentsupplied to the uring the charge supphed to said battery,-

and means under the control of said meter for alterin said standard whenthe battery becomes in 1y charged, whereby the output from said sourcemay be reduced to a desired amount according to preadjustment of saidregulator.

15. In an electrical system, a battery intermittently discharging forvarying periods, means for recharging said battery, means for regulatingthe recharging current,

and means brought into 0 eration only after a charge equal to theprevious discharge plus an amount sufiicient to com ensate for batterylosses has been suppli to the' battery,

said last mentioned means coiiperating with said regulating means tovary the effect thereof on said charging current.

16.. An electric regulator comprising a variable pressure rheostatadapted to be connected 1n series with a generator shunt field windingto regulate the generator output, a current responsive coil adapted tobe connected in the external circuit of the generator for controllingsaid variable pressure rheostat, a voltage responsive coil adapted to beconnected across the generator terminals and alsoadapted to control saidvariable pressure rheostat, and means for permitting the energization ofsaid voltage responsive coil, said means including an integratingmeter.-

17. In a car lighting system, in combina- I tion, a generator having ashunt field, a main circuit for said generator, a storage batteryconnected across said main circuit, an inte: grating meter connected inseries with said storage battery to. measure the electrical energysupplied'thereto, a regulating solenoid comprising a shunt coil and aseries coil for controlling the generator output,-

said shunt coil being normall inert, whereby said enerator is regulatedor constant current y said series coil, and connections between saidregulating means and said meter for permitting the energization of theshunt coil whenthe battery predetermined charge.

i 18. In combination, a enerator, a storage battery tobe charged tiereby, a regulator for the generator, an ampere hour meter in hasreceived a certain the battery circuit for measuring the charge anddischarge of the battery, and means under the control of the ampere hourmeter and associated with the generator regulator whereby when apredetermined charge has been given to the battery, the standard offieldexcitation of the generator is reduced so as to prevent furthercharging of the battery.

19.. A generator, a storage battery, a generator regulator causing thegenerator to charge the battery at a suitable rate to a predeterminedmaximum value, means for measuring the quantity of current delivered tothe battery, means or changing the characterof operation of thegenerator regulator so that when a predetermined charge has beendelivered to the battery the generator regulator will act to preventfurther charge by causing the generator re lator to maintain a lowervoltage on t e battery, and means to prevent such action. of thegenerator regulator until said redetermined measured charge has been deivered to the batter 20. n a car lighting system, in combination, agenerator having a shunt field, a main .circuit for said generator, astorage battery connected across said mam circuit,

an integrating meter connected in series with 98 and the batterycharging current tapered off.

v21. In a car lighting system, in combination, a generator, having ashunt field, a main circuit for said generator, a storage batteryconnected across said main circuit, an integrating meter connected inseries with said storage batter to measure the electrical energysupplied t ereto, a regulating solenoid comprising a shunt coil and-aserles coil for controlling the generator out-put, said shunt coil beingnormally inert, whereby said enerator is regulated for constant currenty said'series coil, and connections between said regulating means andsaid meter for permitting a gradual increase in the energization of saidshunt coi l whereby the energization of said series 0011 is decreasedand the battery charging current tapered 05, said means including avibrati contact arragged ,m a shunt circuit aroun said shunt coi i 92.In a car lighting system, in -combination, a generator aving'ashuntfield winding', a variable pressure rheostat connected 1 in theshunt field circuit, an external circuit supplied by said generator, astorage battery and lamps connected in parallel branches across saidexternal circuit, electro-ma netic means for controlling said variab epressure rheostat to maintain the generator current substantiallyconstant during the charging of the battery, a meter connected in thebattery circuit, a circuit-closer associated with said meter, and meanscooperatin with said electro-magnetic means adapte when energized by theoperation of said circuit-closer to cause said rheostat to reduce thegenerator current and thereby reduce the battery charging current.

23. A car lighting system having a generator, a storage battery, lamps,an automatic electro-responsive regulator for regulating the generatorto compensate for variations in speed and to maintain sufficientgenerator voltage when the generator is above critical speed to chargethe battery, and means to measure the battery output and input andcontrolling the regulator so as to cause the generator to restore adefinite number of ampere hours charge to the battery after a definitenumber of ampere hours discharge.

24. In a car lighting system, a variable speed generator, a storagebattery to be charged thereby, means for measuring the current suppliedto said battery or discharged thereby, a regulator for said generator,current responsive means for operating said regulator, and voltageresponsive means also adapted to operate said regulator, one of saidregulator operating means being under control of said measuring means,whereby the character of regulation is varied in accordance with thestate of charge of said battery.

25. In a car lighting system, a variable speed generator, a storagebattery to be charged thereby, means for measuring the current suppliedto said battery or discharged thereby, a regulator for said generator,operating means for said regulator,

and auxiliary means cooperating to afi'ect the operation of saidregulator, said auxiliary means being under control of said measuringmeans, whereby the'character of regulation is varied in accordance withthe state of charge of said battery.

26. In an electrical system of generation and regulation, a variablesource of supply, a storage battery to be charged thereby, means forcausing said source to deliver a certain output, said means also adaptedto cause said source to deliver a different output, and means formeasurin the current supplied to said battery or disc arged thereby,said measuring means also operating to determine which of said outputsshall be delivered by said source depending on the state of charge ofthe battery.

27. In a carlighting system, a generator, a storage battery to becharged thereby, a regulator'for controlling the generator outputthroughout the operation of the generator, .electro-magnetic meansincluding a current-responsive coil for operating said regulator, anampere hour meter in series between the generator and battery andresponding to battery charging and discharging current, a normallylneffective modifying coil adapted when energized to modify theoperation of said regulator, and means whereby the ampere hour meter,when a redetermined measured charge is in the attery, will cause aneffective current to flow in said modifying coil, thereby causin said ofsaid modifying means to thereby cause said regulator to change thegenerator outut. 1 p In witness whereof, I have hereunto subscribed myname in the presence of two witnesses.

. WILLIAM L. BLISS.

Witnesses CHARLES CHANDLER, WM. A. TURBAYNE.

